Ring sideroblasts and sideroblastic anemias

The sideroblastic anemias include both hereditary and acquired conditions. The two most common forms of congenital sideroblastic anemia, i.e. the X-linked form due to an ALAS2 mutation and the autosomal recessive form due to SLC25A38 mutations, have similar hematologic pictures but completely different clinical courses. Overall, XLSA is a benign disorder that generally responds to pyridoxine with substantial amelioration of anemia; prevention and treatment of iron overload is also important and can be generally achieved through phlebotomy. By contrast, the congenital autosomal recessive congenital sideroblastic anemia due to SLC25A38 mutations is a severe disease, not responsive to pyridoxine and with a clinical course very similar to that of thalassemia major: allogeneic stem cell transplantation should, therefore, be considered in young patients with this disease.